Automatic starter control



Dec. 15, 1936; H MAURER 2,064,350

AUTOMATIC S TARTER CONTROL Filed Oct. 27, 1955 2 Sheets-Sheet 2 INVENTOR BY M TORNEY Patented Dec. 15, 1936 UNITED STATES PATENT OFFICE AUTOMATIC STARTER CONTROL Application October 27,

11 Claims.

The present invention relates to an automatic starter control for internal combustion engines and more particularly to a protective device for limiting the time of cranking in case the engine refuses to start, and for preventing undesired actuation of the starting mechanism in case the usual automatic lock-out becomes ineffective for any reason.

It is an object of the present invention to provide a novel control device of the above character which is reliable and eiiicient in operation and simple and economical in construction.

It is another object to provide such a device which is capable of regulating the cranking time within satisfactory limits.

It is a further object to provide such a device which is particularly adapted to protect against generator failure in automatic starting mechanisms using a generator lockout.

It is another object to provide such a device which protects against all forms of generator failure whether mechanical or electrical.

Further objects and advantages will be apparent to those skilled in this art from the following description taken in connection with the accompanying drawings in which:

Fig. 1 shows semi-diagrammatically a preferred embodiment of the invention used in conjunction with a well known commercial type of automatic starting mechanism; and

Fig. 2 is a similar showing of the invention embodied in a starter control of the combined generator and intake vacuum operated type.

Referring first to Fig. 1 of the drawings, there is illustrated a starting system including a battery I, grounded at 2 and connected by a lead 3 to an automatic starter control element 4. This control element which, as illustrated, is of a wellknown commercial form, includes a magnetic starting switch 5 and a series coil 6 connected by a lead 1 to a starting motor SM which is grounded at 8 to complete the starting circuit.

A control circuit for the magnetic starting switch 5 is illustrated comprising a lead 9 connected to the battery lead 3, a manual switch H which is preferably the ignition switch of the engine, leads l2 and I3, solenoid [4 of the magnetic switch, lead i5, fixed contact [6, and movable contact ll mounted on spring strip l8 which is grounded at IE) to complete the control circuit.

Spring strip It has a pendulous weight 2| mounted on the end thereof in position to be engaged by a roller 22 mounted on the free end of lever 23 which is pivoted at 24 in such manner that downward movement of the lever causes the 1933, Serial No. 695,423

roller 22 to engage the weight 2| and bend back the spring strip I8, thereby opening contacts l6, ll. The lever 23 is normally maintained in its upper position by a spring 25 but is moved downward by a magnetic plunger 26 having flanges 21 and 28 fixed thereto in position to engage a pin 29 extending laterally from said lever.

Plunger 26 is normally maintained in its upper position by means of a spring 3!, in which position it is held during cranking by the magnetic effect of the series coil 6. A shunt coil 32 is provided for attracting the plunger 26 and causing it to actuate the lever 23 to open contacts 16, I! when the engine starts. One end of this coil is connected by a lead 33 to the starting motor side of the starting switch 5, and its opposite end is grounded by a lead 34. A lock-out coil 35 is connected at one end to the ground lead 34 and at the other end by a lead 36 to an enginedriven generator G whereby operation of the generator maintains the plunger 26 in its lower position as long as the engine is self-operative. The field 31 of the generator G is preferably separately excited from the battery I under the control of the ignition switch II as by means of a lead 38 whereby the eiiectiveness of the generator as a lock-out control at low speeds in increased.

According to the present invention, auxiliary means indicated generally at 40 are provided for looking out the starter control after a predetermined time of cranking or in case of generator failure of any kind. As here illustrated, this means comprises a fixed contact 39 connected to the lead l3, and a movable contact 4| mounted on a spring strip 42 of bimetal or thermostatic material which is suitably anchored at one end as indicated at 43 and which is connected by a lead 44 to the lead l2 of the control circuit.

A heating coil 45 for the bimetal is connected at one end to the lead l2 of the control circuit and at its other end to a contact 46 mounted on the free end of the bimetal and insulated therefrom. Contact 46 normally engages a cooperating contact 41 mounted on a spring strip 48 an chored at 49 and connected by a lead 5| to the generator lead 36. The heating circuit is thus completed to the ground through the generator, the connection being such that the voltage of the generator opposes the flow of current through the heating circuit, and during the normal selfoperation of the engine, the heating circuit is thereby maintained substantially deenergized.

The bimetal 42 is arranged normally to hold the contact 4| against the contact 39 and to press the contact 46 against the contact 41 suiiiciently to bend the spring strip 48 slightly away from a stop provided therefor. The bimetal is mounted with its low expansion side on top whereby heating the bimetal causes it to bend upward, first opening contacts 39, ll, thereby breaking the control circuit, and thereafter, when the spring strip l8 engages the stop 52, opening contacts 4i and thereby breaking the heating circuit.

In the operation of this embodiment of the invention, starting with the parts in the positions illustrated, closure of tr e ignition witch l 1 cornpletes the control circuit through the contacts ll, 39, solenoid and contacts :8, ll whereby the starting switch 5 is closed and cranking initiated. When the engine starts, the shunt coil 32 of the automatic starter control element 4 overcomes the series coil and causes lever 23 to engage the weight 2% and open contacts l6, ll, thereby opening the control circuit and stopping the cranking operation. The generator G thereupon builds up and actua-tes the look-out coil 35 to hold the plunger in its lower position as long as the engine is self-operative, and thus prevent undesired operation of the starting mechanism.

When the ignition switch I l is closed, as above set forth, the heating circuit is completed through the heater coil to, contacts 48, ll, lead 5i and the generator G to the ground, and since the voltage of the generator is comparatively low during cranking, the bimetal strip 42 gradually becomes heated up. If the engine fails to start for any reason after a predetermined time of cranking, the bimetal will heat up sufficiently to open contacts 39, 4% whereby the control circuit is broken and cranking ceases. Thereafter, the temperature of the bimetal 42 is controlled by the opening and closing of contacts 45, 47 so as to constantl maintain contacts 35, ll open as long as the ignition switch H is kept closed. The cranking operation may be repeated by opening the ignition switch for a sufficient length of time to allow the bimetal to cool off, and then reclosing said switch. I will be understood that contacts 46, i? are arranged to keep the bimetal 32 at such temperature as to insure under these circumstances a satisfactory short time delay before closure of contacts 39, ll of the control circuit.

In the operation of the auxiliary control device in case of generator failure, two situations may be encountered. If the generator fails by reason of a burning out of the field coil or the failure of the third brush, or by a failure of the mechanical drive for the generator from the engine, the generator becomes in effect a ground connection of low resistance for heater circuit. The coil 35 thereupon rapidly heats up the bi metal 42 and opens contacts 41, 35, thus breaking the control ci cuit and maintaining it open as long as the ignition switch is closed. There will be of course a f w closures of the starting 5 itch during the time that the bimetal is being heated but such unnecessary actuation of a conventional starter drive, when the engine is running, merely causes a clicking noise as tr e drive pinion engages the rotating flywheel of the engine, and does not damage the starting mech anism. If such operation or" the engine with a defective generator is continued over a long period of time, the battery charge will of course become depleted. This device therefore subserves the purpose of an audible alarm to the extent indicated to remind the operator to have the generator repaired. that the heating up of these circumstances is a few seconds.

In the second situation, the generator may fail by a break tlie armature circuit of the generator such as might be caused by failure of one of the main brushes. In this case, the lockout coil 35- is placed in series with the heater circult, since such lock-out coil is designed to be effective at 001 paratively low voltages, the ciu'rent traversin the heating coil and the look-out coil 35 is amply suflieient to maintain the plunger 26 its retracted position so that the starting mechanism is not operated. This current will ordinarily be too small to cause any substantial heating effect on the bimetal E2, but if such heating efiect should take place, it would merely open contacts 39, M and thereby further insure against operation of the starting mechanism.

It will be understood that the coil 35, even though energized by the full battery voltage, is not sufiicient to initially move the plunger 26 away from its upper position, this function being accomplished by the coil 32. A restart of the engine in case of generator failure as just docribed may therefore be obtained by merely opening the ignition switch and reclosing the same. Cranking wil ta e place as usual until the engine starts, WQETCEUDOH the coil 35 performs its lock-out function by battery current instead of by generator current.

In the embodiment of the invention illustrated It will be understood the bimetal 42 under matter of only a very in Fig. 2, there is shown a starting circuit in cluding a battery 60, grounded at 6| and connected by a lead 52 to a magnetic starting switch 53. Switch 33 is connected by a lead 64 to a starting motor SM which is grounded at 65 to complete th starting circuit.

A control circuit for the starting switch 63 is provided including a manual ignition switch 58 connected by lead 87 to the battery lead 62, a thermostatic control device indicated generally at 88 connected by a lead 69 to the ignition switch, and an intake vacuum control device indicated generally by numeral ll connected by a lead 72 to the thermostatic device. The vacuum control ll is connected by a lead 13 to a solenoid is controlling the starting switch 63, the solenoid 54 being grounded through the engine-driven generator C- by means of a lead 75. The generator G is of conventional form but its field it is preferably separately excited from the batter 66 by means of a. lead 17, similarly to the generator d scribed in connection with the embodiment of the invention illustrated in Fig. l.

The thermostatic device 33 is the same as that illustrated in Fig. l and previously described, the parts thereof being given the same designating numerals, and the heating circuit thereof is completed through the generator G by means of a lead 5! as above set forth.

The intake vacuum control device as here illustrated comprises a casing element 78 providing a chamber 18 adapted to be connected by a nipple 61' to the intake manifold 80 of the engine to be started. The chamber 19 is closed by a flexible diaphragm 83 5 suitable material having attached to the center thereof a plunger 83 which controls a set of contacts. This plunger is guided by a cap member 84 and carries at its upper end a bridging conductor 85 normally connecting contacts 86 and 87 which form the ter 68 under the control of the ignition switch it minals of leads I2 and 13. Contacts 86 and 81 are also bridged by a resistor 88 having such a value as to limit battery current passing therethrough to a holding value for the solenoid 14.

In the operation of this embodiment of the invention, closure of the ignition switch 66 completes the control circuit from the battery through contacts 4!, 39 of the thermostatic device 68, contacts 86, 85, 81, solenoid l4 and generator G to the ground. Solenoid 14 is thereby operated to close the starting switch 53 and initiate the cranking operation. As soon as any appreciable vacuum is built up in the intake manifold by the cranking of the engine, this vacuum is transmitted to the chamber 19 whereby the diaphragm 82 is deflected and bridging conductor 85 moved out of engagement with contacts 86, 81. The resistor 88 is thus inserted in the control circuit, but inasmuch as this resistor permits a holding current for the solenoid 14 to pass, the starting switch 63 is maintained closed and cranking continues. When the engine becomes self-operative, the voltage of the generator opposes the flow of current through the control circuit, deenergizing the same and permitting the starting switch to open. Thereafter, the starting switch will not be reclosed unless the vacuum in the intake manifold falls to an inoperative value at the same time that the generator G is not rotating sufficiently fast to prevent full energization of the control circuit.

At the same time that the control circuit is closed by the ignition switch 66, the heating circuit through the thermostatic device 68, lead and generator G is completed, whereby during cranking the bimetal 42 is gradually heated up. If the engine fails to start after a predetermined time of cranking, contacts 4!, 39 will open, thus breaking the control circuit and interrupting the cranking operation as described in the operation of the first embodiment of the invention.

Should the generator fail to operate by reason of an open field circuit or a rupture in themechanical driving connection from the engine, the heating circuit is grounded through the generator, and the bimetal 42 becomes rapidly heated whereby contacts 39, 4| are opened and operation of the starter mechanism is thus pre-- vented as long as the ignition switch 66 remains closed. Restarting may be secured as before by opening the ignition switch for a time sufficient to allow the bimetal to cool down and then repeating the initial operation.

Should the generator fail by reason of a break in the armature circuit, there is then no ground connection for the control circuit, and solenoid T4 is therefore maintained deenergized.

It will be understood that if the starting mechanism for the engine should jam for any reason, the situation, so far as the novel starter control is concerned, is the same as though the generator drive had failed. In other words, the generator acts as a ground connection for the heater circuit whereby the bimetal is rapidly f heated and the control circuit and starting circuit are thereby opened.

It has been found in the operation of automatic starter controls in which the field winding of the generator is separately excited, that the voltage induced in the field winding when the battery connection is broken is sometimes suflicient to energize the magnetic starting switch and cause a momentary closing of the starting circuit. Thus, for instance, in the circuit illusa trated in Fig. 2, after the engine has been operating, if the ignition switch 66 is opened in order to stop the engine, the voltage induced in the field winding 16 caused by the breaking of the battery connection causes a current to flow through leads Ti, 69, 44, contacts 4!, 39, resistor 88, lead 73, solenoid l4 and lead 15 back to the generator. This inductive surge of current sometimes energizes the solenoid 14 sufficiently to momentarily close the starting switch 63.

According to the present invention, a resistor is placed in parallel Wtih the field winding 16 in order to dissipate this induced voltage, and, as here shown, this resistor is constituted by the heating element 45 of the control device 68. It will be noted that this heating element is also in parallel with the solenoid 14 of the magnetic starting switch, thus forming, when the ignition switch 66 is opened, a circuit comprising leads TI and 69, resistor 45, contacts 46, 41 and lead 5|; which circuit is in shunt with the circuit comprising leads 1'! and 69, contacts 4|, 39, lead 12, resistor 88, lead 13, solenoid l4 and lead 15. Since the resistor 45 is substantially non-inductive, and the solenoid M has considerable selfinductance, it will be obvious that the value of the resistor 45 is not at all critical. In practice, suitable values for the resistor 45 in so far as its heating function is concerned have been found to be well adapted for the function of preventing the energization of the magnetic starting switch from the field winding.

Itwiil be noted that in the construction illustrated in Fig. l the resistor 45 is also arranged in shunt with the generator field winding so as to dissipate the induced voltage thereof when the ignition switch is opened, in the same manner as set forth above. This induced voltage, although but momentary, often rises to several times the normal impressed voltage, so that the use of a non-inductive shunt to dissipate it harmlessly is advantageous not only with respect to the operation of the starter control but also as a protection to the ignition coil, which is otherwise subjected thereto if the breaker points of the ignition circuit are closed at the time that 1e ignition switch is opened.

Although certain embodiments of the invention have been shown and described in detail, it will be understood that other embodiments are possible and that various changes may be made in the features and arrangements of the structure without departing from the spirit of the invention as defined in the claims appended hereto.

What is claimed is:

1. In an automatic mechanism for starting internal combustion engines and restarting in case of engine stall, a manual control switch for the starting mechanism, means responsive to self operation of the engine for deenergizing the starting mechanism and preventing actuation thereof during the self-operation of the engine, and auxiliary means for deenergizing the starting mechanism and preventing actuation thereof without interfering with the operation of the engine in case the engine does not start after a predetermined time of cranking, said first means being operative to prevent actuation of said auxiliary means, said auxiliary means thereby becoming operative upon failure of said first means, said manual switch being also arranged to control the energization of the auxiliary means and said auxiliary means being arranged when deenergized to return to inoperative position whereby in case of failure of the first said means,

a restart may be secured by opening and reclosing said manual switch.

2. In combination with an internal combustion engine, an electrical system therefore comprising a battery, a starting system including a starting motor, an engine-driven generator and an automatic starter control for energizing the starting motor in case of engine stall including a magnetic starting switch and a control circuit therefor energized from said battery, said generator being connected in said control circuit in opposition to said battery for preventing energization of the control circuit during self-operation of the engine, separate auxiliary automatic means energized from said battery for preventing operation of the starting system after a predetermined time of cranking, said generator also being connected in circuit with said auxiliary means in opposition to said battery for deenergizing said auxiliary means and preventing operation thereof during selfoperation of the engine whereby an open circuit in the generator opens the control circuit, and a short circuit in the generator permits the auxiliary means to render the starting system inoperative.

3. In combination with an internal combustion engine, an electrical system therefor including a battery, an engine-driven generator, a starting system including a starting motor and an automatic starter control for energizing the starting system in case of engine stall including a magnetic starting switch and a control circuit therefor energized from said battery, said generator being connected in said control circuit in opposition to said battery for preventing the energizaticn of the control circuit during selfcperation of the engine, thermostatic means heated. by current from said battery for limiting the period of operation of the starting system and thereafter maintaining the same inoperative while maintaining the operative condition of the engine, said generator being also connected in circuit with said thermostatic means in opposition to said battery for preventing operation of the thermostatic means diu'ing self-operation of the engine whereby a short circuit in the generator permits the thermostatic means to interrupt the operation of the starting system after a predetermined tiine and maintain it inoperative without impairing the operation of the engine.

4. In combination with an internal combustion engine, an electri al system therefor including an engine-driven generator and a starting system comprising a motor for cranking the engine and a magnetic starting switch for the motor, a control circuit for said switch, means actuated by said generator for preventing the energization of said control circuit during self-operation of the engine, means for opening said control circuit after a predetermined time of energization thereof, and means whereby the voltage of the generator opposes the operation of said opening means and prevents energization thereof during self-operation of the engine.

5. In combination with an internal combustion engine, an electrical system therefor including a battery, an engine-driven generator and a starting system having a starting motor and a magnetic starting switch, a control circuit for said switch, electromagnetic means actuated by said generator for preventing closure of the control circuit during self-operation of the engine, thermostatic means arranged to be heated by current from said battery for opening said control circuit after it has been closed a predetermined time, and means whereby the voltage of the generator opposes the heating of said thermostatic element during selfoperation of the engine.

6. In combination with an internal combustion engine, an electrical system therefor including an engine-driven generator having a field winding and a starting system including a starting motor and a magnetic starting switch therefor having a magnet coil, 2, control circuit including the field winding of said generator and the coil of said starting switch, said field winding and coil being arranged in parallel branches thereof, a manual control switch in the control circuit for controlling the excitation of the field winding and the switch coil, and a non-inductive resistance in shunt with said coil for preventing excitation of the coil from the generator to cause closure of the magnetic starting switch when said manual switch is opened.

'7. In combination with an internal combustion engine, an electrical system therefor including a battery, an engine-driven generator and a starting system including a magnetic starting switch, common means for controlling the excitation of the generator and the magnetic starting switch from the battery, and means for opening said starting switch after a predetermined time of cranking, said opening means being arranged to prevent excitation of the magnetic starting switch from the generator when the battery connection is broken.

8. In combination with an internal combustion engine, an electrical system therefor including a battery, an ignition circuit, an engine-driven generator having a field winding and a starting system including a magnetic starting switch coil, a single switch for jointly controlling the excitation of said ignition circuit, said field winding and said magnetic starting switch coil from the battery, and means operative when the control switch is opened to absorb and dissipate the voltage induced thereby in said field winding and prevent it from energizing said ignition circuit or causing the coil to effect closure of the starting switch.

9. In combination with an internal combustion engine an electrical system therefor including a battery, an engine-driven generator having a field winding and a starting system in cluding a magnetic starting switch, a switch for jointly controlling the excitation of said field winding and of the magnetic starting switch from the battery, and means for opening said starting switch after a predetermined time of cranking, said means including a non-inductive resistor in parallel with said generator field winding for dissipating the voltage induced therein when the control switch is opened.

10. In an automatic starter control for inte nal combustion engines, an electrical system comprising a starting circuit including a battery, a starting motor and a magnetic starting switch having an actuating coil, a control cir cuit for the starting switch including an enginedriven generator in series with the coil of the starting switch arranged to oppose the flow of battery current therethrough, and a thermostatic device for opening the circuit through said coil, said thermostatic device having a heating coil in the control circuit also in series with said generator.

11. In an automatic starter control for intercombustion engines, an electrical system comprising a starting circuit including a battery, a starting motor and a ma starting switch having an actuating coil, a control circuit for the starting switch including an enginedriven generator in series with the coil of the starting switch arranged to oppose the flow of battery current therethrough and having a field winding energized from said battery through said control circuit, and a thermostatic device for opening the circuit through the coil of the starting switch, said thermostatic device having a heating coil in the control circuit in parallel with the coil of the starting switch.

PAUL H. MAURER. 

